Thanks for your response! The official answer is indeed C.
However, I came up with choice A.
We are just asked to find out the fraction of the cube that is red.
When statement (1) tells us that each of the 3 faces of cube is exactly half red, then why should I worry to know about other 3 surfaces. Do not I know from this statement alone that 25% of the cube is red? (since I don't expect 2nd statement to contradict 1st statement.)
What fractional part of the total surface area of cube C is red?
(1) Each of 3 faces of C is exactly 1/2 red.
(2) Each of 3 faces of C is entirely white.
Thanks for the your response and explanation!
Statement 1 does not give any information about remaining 3 faces, so insufficient.
Statement 2 does not give any information about remaining 3 faces, so insufficient.
Combining statement 1 and 2 we know that out of 6 faces, 3 are entirely white and remaining 3 are half red, so a total of 1.5 faces out of 6 are red and hence the required fraction is 1.5/6 or 0.25.